Manufacture of steel.



UNITED STATES Patented November 15, 1904.

PATENT OFFICE.

VMANUFACTURE OF STEEL.

SPECIFICATION forming part of Letters Patent N 0. 774,958, datedNovember 15, 1904. Application filo! July 1'7, 1903. Serial No. 166,012.(No specimens.)

T0 al whom it may concern:

Be it known that I, TOLMIE JOHN TRESIDDER, a subject of the King ofGreat Britain and Ireland. residing at Atlas Iron and Steel Works,Sheifield, in the county of York, England, have in vented certain newand useful Improvements in the Manufacture of Steel, of which thefollowing is a specification.

This invention has for its object to provide steel of such a characterthat while readily receptive of a fibrous structure under suitabletreatment it can retain that fibrous structure under conditions thatwould ordinarily produce a crystalline structure, such, in particular,as the sudden chilling from a very high temperature necessaryin theprocess of facehardening after supercarburization. The said steelaccording to this invention has the following composition, namely: iron,carbon, manganese, nickel, and tungsten in or about the followingproportions in each ten thousand parts, by Weight,of the steel mixture:carbon, from twenty-eight to thirty-two parts, by weight; manganese,fromtwenty-five to thirty parts, by weight; nickel, from two hundred andtwenty-five to two hundred and fifty parts, by weight; tungsten, fromtwenty-eight to thirty-two parts, by weight, the remainder being ironwith such impurities as usually cannot be avoided in practice, such assilicon, sulfur, phosphorus, cobalt, arsenic, copper, and the like.Silicon may be present up to ten or fifteen parts, by Weight, Withoutdetriment, while the others, if their presence cannot be avoided, shouldbe present in as small a quantity as is possible.

The following is the preferred Way of proceeding in manufacturing thesteel having the above composition: The charge consisting of about onehalf good hoematite or Swedish pigiron and the other half good puresteel-scrap is melted on the Siemens hearth until the impurities havebeen eliminated, and the carbon, as judged by fracture of a spoonsample, is under one-fifth per cent., and then nickel, in the form ofrondelles, of metallic nickel is thrown into the bath and stirredtherein. l/Vhen this is thoroughly incorporated, (which will usually bein about ten minutes,)red-hot ferromanganese is added in such quantityas experience shows will after allowing for the necessary loss leave thedesired percentage of manganese. When the said ferromanganese has beenwell stirred in, the tungsten is added, preferably, in the condition ofred-hot ferrotungsten, containing about one-third tungsten andtwo-thirds iron. No allowance need be made for loss of tungsten. As soonas the ferrotungsten has had time to become thoroughly mixed the steelis tapped into a ladle and cast into an ingot. The ingot thus producedis of such a character that before being reheated it can be laid downand allowed to 0001 Without its being liable to spontaneousdisintegration; but, if desired, it can while still hot be at once takento the forging-press or rolling-mills to be forged or rolled into platesWithout any special precautions being necessary, and if ordinary stepsbe taken for removing scale the surface will not require to be machined;but if it be desired to machine it machining can be done with facility.

Having now particularly described and as certained the nature of thesaid invention and in What manner the same is to be performed, I declarethat what I claim is- 1. Steel composed of iron, carbon, manganese,nickel and tungsten, the proportion of manganese not exceeding one percent. of the Whole.

2. Steel containing iron and carbon, manganese, nickel and tungsten inabout the following proportions: carbon, 0.28 to 0.32 per cent.manganese,0.25 to 0. 30 per cent. nickel, 2.25 to 2.50 per cent; andtungsten, 0.28 to 0.32 per cent, the remainder being iron.

3. Steel composed of iron, carbon, manganese, nickel and tungsten, thesum of the substances other than iron being less than ten per cent. ofthe whole.

In testimony whereof Iaffix my signature in presence of two witnesses.

TOLMIE JOHN TRESIDDER.

WVitnesses:

EDWARD CHARLEs HAMMOND, WILLIAM GERALD REYNoLDs.

